Akimitsu Ichihara,Nozomu Nishitani,Tadahiko Ogawa,Takuya Tsugawa. Northward-propagating nighttime medium-scale traveling ionospheric disturbances observed with SuperDARN Hokkaido HF radar and GEONET[J]. ADVANCES IN POLAR SCIENCE, DOI: 10.3724/SP.J.1085.2013.00042.